A tire includes: a tread band on which is defined a radially outer tread surface, a first plurality of blocks provided on the tread band, and at least a first sipe of the restrained type extending on at least one block of the first plurality in a substantially axial direction defined on the tread band. The first sipe is configured so as to define, between a first and a second block portion divided by the first sipe, at least two separate and distinct couplings of the male/female type, such as to prevent the mutual displacement of the block portions in any direction which, at the block, is substantially tangential to the tread surface, and such as to permit mutual displacement of the block portions in a direction incident to the tread surface. In addition, the first sipe does not intersect any other sipe of the restrained type within the block.